// patterns/doubledispatch/DoubleDispatch.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Using multiple dispatching to handle more
// than one unknown type during a method call
// {java patterns.doubledispatch.DoubleDispatch}
package doubledispatch;

import patterns.trash.*;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

class AluminumBin extends TypedBin {
    @Override
    public boolean add(Aluminum a) {
        return addIt(a);
    }
}

class PaperBin extends TypedBin {
    @Override
    public boolean add(Paper a) {
        return addIt(a);
    }
}

class GlassBin extends TypedBin {
    @Override
    public boolean add(Glass a) {
        return addIt(a);
    }
}

class CardboardBin extends TypedBin {
    @Override
    public boolean add(Cardboard a) {
        return addIt(a);
    }
}

class TrashBinSet {
    private List<TypedBin> binSet = Arrays.asList(
            new AluminumBin(),
            new PaperBin(),
            new GlassBin(),
            new CardboardBin()
    );

    @SuppressWarnings("unchecked")
    public void sortIntoBins(List bin) {
        bin.forEach(aBin -> {
            TypedBinMember t = (TypedBinMember) aBin;
            if (!t.addToBin(binSet))
                System.err.println("Couldn't add " + t);
        });
    }

    public List<TypedBin> binSet() {
        return binSet;
    }
}

public class DoubleDispatch {
    public static void main(String[] args) {
        List<Trash> bin = new ArrayList<>();
        TrashBinSet bins = new TrashBinSet();
        // ParseTrash still works, without changes:
        ParseTrash.fillBin("doubledispatch", bin);
        // Sort from the master bin into the
        // individually-typed bins:
        bins.sortIntoBins(bin);
        // Perform sumValue for each bin...
        bins.binSet()
                .forEach(tb -> Trash.sumValue(tb.v));
        // ... and for the master bin
        Trash.sumValue(bin);
    }
}
/* Output: (First and Last 10 Lines)
Loading patterns.doubledispatch.Glass
Loading patterns.doubledispatch.Paper
Loading patterns.doubledispatch.Aluminum
Loading patterns.doubledispatch.Cardboard
weight of patterns.doubledispatch.Aluminum = 89.0
weight of patterns.doubledispatch.Aluminum = 76.0
weight of patterns.doubledispatch.Aluminum = 25.0
weight of patterns.doubledispatch.Aluminum = 34.0
weight of patterns.doubledispatch.Aluminum = 27.0
weight of patterns.doubledispatch.Aluminum = 18.0
...________...________...________...________...
weight of patterns.doubledispatch.Aluminum = 93.0
weight of patterns.doubledispatch.Glass = 93.0
weight of patterns.doubledispatch.Paper = 80.0
weight of patterns.doubledispatch.Glass = 36.0
weight of patterns.doubledispatch.Glass = 12.0
weight of patterns.doubledispatch.Glass = 60.0
weight of patterns.doubledispatch.Paper = 66.0
weight of patterns.doubledispatch.Aluminum = 36.0
weight of patterns.doubledispatch.Cardboard = 22.0
Total value = 1086.0599818825722
*/
